//The contents of this file are subject to the Mozilla Public License Version 1.1
//(the "License"); you may not use this file except in compliance with the 
//License. You may obtain a copy of the License at http://www.mozilla.org/MPL/
//
//Software distributed under the License is distributed on an "AS IS" basis,
//WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 
//for the specific language governing rights and
//limitations under the License.
//
//The Original Code is "The Columba Project"
//
//The Initial Developers of the Original Code are Frederik Dietz and Timo Stich.
//Portions created by Frederik Dietz and Timo Stich are Copyright (C) 2003. 
//
//All Rights Reserved.
package org.columba.core.base;

public class Mutex {
    private boolean mutex;

    public Mutex() {
        mutex = false;
    }

    /**
     *
     * @return true the mutex was indeed taken anew, false if calling thread already had mutex.
     */
    public synchronized void lock() {
        while (mutex) {
            try {
                wait();
            } catch (InterruptedException e) {
                if (Thread.currentThread().isInterrupted()) {
                    // gota go now
                    throw new RuntimeException(e);
                }

                // else keep waiting
            }
        }

        mutex = true;
    }

    public synchronized void release() {
        mutex = false;
        notify();
    }
}
